The present invention relates to an electric rice cooker and, more particularly, to an electric rice cooker for electrically heating a desired amount of rice placed in a pot or kettle with a proper amount of water and for automatically maintaining the cooked rice at a predetermined temperature in the hot plate mode. (It is noted that the term "hot plate" here indicates a device which keeps food, especially rice, warm.)
Electric rice cookers are very useful appliances in countries (including Japan) where people consume rice as a staple food, and have become prevalent in the households of such countries.
As is known among those who are skilled in the art, when cooking the rice, the temperature must be properly controlled so that the rice properly absorbs water.
In a conventional electric rice cooker such as an electric rice cooker disclosed in Japanese Patent Disclosure (KOKAI) No. 53-63174, the cooking heater is deenergized after a predetermined time interval, determined solely by a delay circuit, has elapsed after cooking is started. When a further given time interval has elapsed, power is supplied again to the cooking heater so as to restore the cooking state. The heater stops heating the rice at the earlier point in time in order to allow the rice to absorb moisture.
However, in the electric rice cooker of the prior art described above, the time interval for allowing the rice to absorb moisture is determined independently of the actual temperature of the kettle, so that the start time for allowing the rice to absorb the moisture, that is, the time for deenergizing the cooking heater, cannot be properly determined in accordance with the actual temperature of the kettle. As a result, the rice can hardly be cooked to the desired softness and stickiness.